Before Sen. Ted Cruz exited the Senate floor on Wednesday evening as the 16-day federal government shutdown was drawing to a close, the Texas Republican got one final dig in at the Obama administration. Cruz, a freshman lawmaker associated with the Tea Party movement, blocked the Senate from voting on the nomination of Tom Wheeler, a Democrat who is the White House’s choice to be chairman of the Federal Communications Commission. The Senate had been scheduled to vote on Wheeler’s nomination Wednesday.

Why did Cruz do this? Because he opposes the DISCLOSE Act, a bill that would require super PACS, corporations, unions and other outside groups to disclose to the Federal Elections Commission when they spend more than $10,000 to air political campaign ads. Democrats and public interest groups have been urging passage of the bill as a way to bring greater transparency to political ad funding, but many conservative groups and lawmakers oppose the legislation. In April, Cruz and other GOP senators wrote a letter to the FCC saying the bill raises “grave constitutional concerns for speech protected by the First Amendment.”

With the bill stalled, some Democrats have suggested that the FCC might be able to use its existing authority over TV broadcasters to require such disclosures. Cruz does not believe the FCC has such authority, and during Wheeler’s confirmation hearing in June before the Senate Commerce Committee, which oversees the FCC, Cruz pressed the nominee on his views about whether the agency possesses such authority. Wheeler dodged the question, saying he needed more time to study the issue. Cruz made it clear at the time that he was willing to hold up the nomination until he is satisfied.

“The Senator is holding the nominee until he gets answers to his questions regarding Mr. Wheeler’s views on whether the FCC has the authority or intent to implement the requirements of the failed Congressional DISCLOSE Act,” Sean Ruston, Sen. Cruz’s communications director, said in a statement emailed to TIME. “Mr. Wheeler had previously declined to give specific answers, but as he’s now expressed his readiness to revisit the Senator’s questions, the Senator hopes to communicate with him soon.”

Chris Lewis, vice president of government affairs at Public Knowledge, a D.C.-based public interest group, pointed out that it would be unusual for a FCC nominee to say how he or she would decide on an issue that hasn’t even come up before the commission. Senate Democrats could force a vote on Wheeler’s nomination, but that would require a 60-vote supermajority.

“In these situations, we’d hope the nominee and the senator would find a way to come to an understanding,” said Lewis, who added that his group is not taking a position on the DISCLOSE Act one way or the other. “There are a lot of important issues that the FCC needs to work on, so the sooner that they are at full strength, the sooner they can address them.”

The FCC, which currently only has three commissioners out of its full five-member commission, faces a host of important issues. The commission is currently weighing new media ownership rules and preparing for a complex wireless spectrum auction aimed at freeing up airwaves for consumer use. The FCC also faces a closely watched legal challenge over its authority to enforce the “Open Internet” rules that are at the basis of net neutrality, the idea that broadband providers shouldn’t discriminate against rival services. In that lawsuit, telecom giant Verizon claims that the FCC overstepped its legal authority.

Wheeler is a well-regarded venture capitalist and former cable and wireless industry lobbyist, who was most recently managing director at D.C.-based firm Core Capital Partners. Wheeler is also a longtime Obama loyalist who spent six weeks in Iowa with his wife during Obama’s first presidential campaign, where they worked the phones and knocked on doors for the candidate. Wheeler has also raised hundreds of thousands of dollars for Obama, according to the Center For Responsive Politics.

Wheeler’s confirmation has been highly anticipated ever since Obama announced his nomination in May. From D.C. to Silicon Valley, tech and telecom companies, public interest groups, and policy experts are eager to see what Wheeler does once he is confirmed.

“We have a lot of questions about what kind of FCC chairman Tom Wheeler is going to be,” said Timothy Karr, senior director of strategy at Free Press, a D.C.-based public interest group. “But he has been nominated by the president and won the approval of the vast majority of the Senate. So it’s time for Senator Cruz to stop holding the process hostage, and let Wheeler do his job. If Cruz doesn’t like Wheeler, he should just vote against him. But it’s time to put the full FCC back to work.”